Array substrate for liquid crystal display device and manufacturing method of the same

ABSTRACT

According to an embodiment, an array substrate for an LCD device includes a substrate; gate lines on the substrate along a first direction; data lines formed along a second direction and crossing the gate lines to define pixel regions; a common line between adjacent gate lines; a thin film transistor at each crossing point of the gate lines and the data lines; red, green and blue color filter patterns sequentially disposed in the pixel regions, respectively; a common electrode over each of the red, green and blue color filter patterns and connected to the common line; and a pixel electrode over the common electrode and connected to the thin film transistor, the pixel electrode overlapping the common electrode.

The present application is a divisional application of application Ser.No. 11/966,835 filed Dec. 28, 2007 now U.S. Pat. No. 7,808,595 whichapplication claimed the priority benefits of Korean Patent ApplicationsNo. 10-2007-0032220 filed in Korea on Apr. 2, 2007 and No.10-2007-0037256 filed in Korea on Apr. 17, 2007. The entire contents ofeach of the above-identified applications are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display (LCD) device,and more particularly, to an array substrate for a liquid crystaldisplay device and a manufacturing method of the same.

2. Discussion of the Related Art

Liquid crystal display (LCD) devices are driven based on opticalanisotropy and polarization characteristics of a liquid crystalmaterial. Liquid crystal molecules have a long and thin shape, and theliquid crystal molecules are regularly arranged along in an alignmentdirection. Light passes through the LCD device along the long and thinshape of the liquid crystal molecules. The alignment of the liquidcrystal molecules depends on the intensity or the direction of anelectric field applied to the liquid crystal molecules. By controllingthe intensity or the direction of the electric field, the alignment ofthe liquid crystal molecules is controlled to display images.

Generally, an LCD device includes two substrates, which are spaced apartand facing each other, and a liquid crystal layer is interposed betweenthe two substrates. Each of the substrates includes an electrode. Theelectrodes from respective substrates face one another. An electricfield is induced between the electrodes by applying a voltage to eachelectrode. An alignment direction of liquid crystal molecules changes inaccordance with a variation in the intensity or the direction of theelectric field.

FIG. 1 is a view of schematically illustrating an LCD device accordingto the related art. In FIG. 1, the related art LCD device 11 includestransparent lower and upper substrates 10 and 30 spaced apart from andfacing each other. The LCD device further includes a liquid crystallayer (not shown) interposed between the lower and upper substrates 10and 30.

Gate and data lines 12 and 20 are formed on an inner surface of thelower substrate 10 and cross each other to define pixel regions P. Thinfilm transistors T are formed at crossing points of the gate and datalines 12 and 20. The thin film transistors T are arranged in a matrixtype. Each thin film transistor T includes a gate electrode 14, anactive layer 16, a source electrode 17 and a drain electrode 18. A pixelelectrode 22 is formed at each pixel region P and is connected to acorresponding thin film transistor T. The pixel electrode 22 is formedof a transparent conductive material, which transmits light well, suchas indium-tin-oxide.

A black matrix 32 is formed on an inner surface of the upper substrate30 that faces the lower substrate 10. The black matrix 25 covers anon-display region, such as the gate lines 12, the data lines 20, andthe thin film transistors T and has a lattice shape surrounding thepixel regions P. A color filter layer is formed in each opening of thelattice of the black matrix 32. The color filter layer includes red,green and blue color filter patterns 34 a, 34 b and 34 c correspondingto the pixel regions P. A transparent common electrode 36 is formed onthe black matrix 32 and the color filter layer 34 a, 34 b and 34 c.

The lower substrate 10 including the gate and data lines 12 and 20, thethin film transistors T and the pixel electrodes 22 may be referred toas an array substrate. The upper substrate 30 including the black matrix32, the color filter layer 34 a, 34 b and 34 c and the common electrode36 may be referred to as a color filter substrate.

The array substrate and the color filter substrate are separatelymanufactured, aligned, and then attached with each other to therebyfabricate a liquid crystal panel. At this time, there is highpossibility that light leakage occurs due to alignment margins. Toprevent the light leakage, the black matrix 32 may have wider width, andit causes decrease in an aperture area.

Accordingly, to solve the problem, a color filter on array structure(COA) type LCD device has been proposed in which the color filter layeris formed on the array substrate.

FIG. 2 is a cross-sectional view of schematically illustrating an arraysubstrate for a COA-type LCD device according to the related art.

In FIG. 2, a thin film transistor T is formed on a transparentinsulating substrate 50, and the thin film transistor T includes a gateelectrode 54, an active layer 58, an ohmic contact layer 60, a sourceelectrode 62 and a drain electrode 64. In addition, a gate line 52 and adata line 66 are formed on the substrate 50. The gate electrode 54 isconnected to the gate line 52, and the source electrode 60 is connectedto the data line 66. Although not shown in the figure, the gate line 52and the data line 66 cross each other to define a pixel region P. Ablack matrix BM and a color filter layer are formed on the substrate 50including the thin film transistor T, the gate line 52 and the data line66. The black matrix BM corresponds to the thin film transistor T andcovers the active layer 58. The color filter layer includes red andgreen color filters 72 a and 72 b, which correspond to respective pixelregions P. The color filter layer further includes blue color filter(not shown).

A transparent pixel electrode 76 is formed on the color filter layer.The pixel electrode 76 is connected to the drain electrode 64.

Since the array substrate includes the color filter layer, it is notnecessary to design by considering alignment margins. Therefore, theaperture area can be more obtained.

By the way, in an LCD device including the array substrate, an electricfield is induced between the pixel electrode 76 and a common electrode(not shown), which is formed on an opposite substrate to the arraysubstrate, and is perpendicular to the substrate 50. The LCD device hasvery narrow viewing angles. To increase the viewing angles of the LCDdevice, an in-plane switching (IPS) mode LCD device has been suggested,in which the common electrode and the pixel electrode are formed on thesame substrate.

FIG. 3 is a cross-sectional view of illustrating an array substrate fora COA-IPS mode LCD device according to the related art. FIG. 4 is aschematic view of explaining dielectric constants of color filterpatterns of FIG. 3.

In FIG. 3 and FIG. 4, a pixel region P is defined on an insulatingsubstrate 80. A thin film transistor T and a color filter layer 96 a, 96b and 96 c, a pixel electrode 98 a and a common electrode 98 b areformed in the pixel region P.

The thin film transistor T includes a gate electrode 84, an active layer88 a, an ohmic contact layer 88 b, a source electrode 90 and a drainelectrode 92. The gate electrode 84 is connected to a gate line 82, andthe source electrode 90 is connected to the data line 94. Although notshown in the figure, the gate line 82 and the data line 94 cross eachother and are disposed at two sides of the pixel region P.

The color filter layer 96 a, 96 b and 96 c is formed over the substrate80 including the thin film transistor T, the gate line 82 and the dataline 94. The color filter layer includes red, green and blue colorfilter patterns 96 a, 96 b and 96 c. A black matrix BM is formed betweenthe thin film transistor T and the color filter patterns 96 a, 96 b and96 c.

The pixel electrode 98 a and the common electrode 98 b are formed overthe color filter patterns 96 a, 96 b and 96 c. The pixel electrode 98 aand the common electrode 98 b are spaced apart from and alternate witheach other. The pixel electrode 98 a is connected to the drain electrode92 and receives signals independently in each pixel region P accordingto operations of the thin film transistor T. The common electrodes 98 bof all the pixel regions P receive a common signal. The common signalmay be a direct current (DC) voltage of about 5 V.

Meanwhile, the color filter patterns 96 a, 96 b and 96 c may be a stripetype, in which the color filter patterns 96 a, 96 b and 96 c invertically or horizontally adjacent pixel regions have the same color.The color filter patterns 96 a, 96 b and 96 c may be formed by a pigmentdispersion method, in which a pigment-dispersed photosensitive materialis applied and then is patterned through a photolithographic process.Here, pigments are used a colored article for the color filter patterns96 a, 96 b and 96 c. The pigments have high lightfastness and heatresistance. The pigment dispersion method simplifies a process offorming the color filer patterns 96 a, 96 b and 96 c.

The green color filter pattern 96 b is thicker than the red and bluecolor filter patterns 96 a and 96 c so that the color purity of thegreen color filter pattern 96 b may be uniformalized with color puritiesof the red and blue color filter patterns 96 a and 96 c.

However, even though the COA-IPS mode LCD device has a larger apertureratio and wide viewing angles, band-shaped speckles may occur due to thecolor filter patterns.

Referring to FIG. 4, when the pixel electrode 98 a and the commonelectrode 98 b are formed over each of the color filter patterns 96 a,96 b and 96 c, an electric field induced between the pixel electrode 98and the common electrode 98 b is influenced by a dielectric constant ofa liquid crystal layer (not shown) in an upper side and by a dielectricconstant of the color filter patterns 96 a, 96 b and 96 c in a lowerside. Accordingly, a first capacitor C_(LC) is formed by the pixelelectrode 98 a, the common electrode 98 b and the liquid crystal layerat each pixel region, and second capacitors C_(CR), C_(CG) and C_(CB)are formed by the pixel electrode 98 a, the common electrode 98 b andthe color filter patterns 96 a, 96 b and 96 c in respective pixelregions. The first capacitor C_(LC) has the same capacitance every pixelregion. The second capacitors C_(CR), C_(CG) and C_(CB) have differentcapacitances because the dielectric constant ∈2 of the green colorfilter pattern 96 b is different from the dielectric constants ∈1 and ∈2of the red and blue color filter patterns 96 a and 96 c. For example,the dielectric constants ∈1 and ∈2 of the red and blue color filterpatterns 96 a and 96 c may be 4±1, and the dielectric constant ∈2 of thegreen color filter pattern 96 b may be 5±1.

Therefore, carriers induced in the color filter patterns 96 a, 96 b and96 c are not smoothly refreshed. This cause afterimages or band-shapedspeckles according to the color filter patterns 96 a, 96 b and 96 c,thereby lowering image qualities.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to an array substrate foran LCD device and a manufacturing method of the same that substantiallyobviate one or more of the problems due to limitations and disadvantagesof the related art.

An advantage of the present invention is to provide an array substratefor an LCD device and a manufacturing method of the same that haveuniform image qualities.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,according to an embodiment an array substrate for an LCD device includesa substrate, gate lines on the substrate along a first direction, datalines formed along a second direction and crossing the gate lines todefine first, second and third pixel regions, thin film transistors atcrossing points of the gate lines and the data lines, red, green andblue color filter patterns sequentially disposed in the first, secondand third pixel regions, respectively, first, second and third commonlines corresponding to the first, second and third pixel regions andreceiving first, second and third common voltages, respectively, whereinthe second common voltage is different from the first and third commonvoltages, a pixel electrode over each of the red, green and blue colorfilter patterns and connected to one of the thin film transistors, and acommon electrode over each of the red, green and blue color filterpatterns and connected to one of the first, second and third commonlines, the common electrode spaced apart from the pixel electrode.

In another aspect, a manufacturing method of an array substrate for anLCD device includes forming gate lines on a substrate along a firstdirection, forming data lines formed along a second direction andcrossing the gate lines to define first, second and third pixel regions,forming thin film transistors at crossing points of the gate lines andthe data lines, forming first, second and third common linescorresponding to the first, second and third pixel regions and receivingfirst, second and third common voltages, respectively, wherein thesecond common voltage is different from the first and third commonvoltages, forming red, green and blue color filter patterns sequentiallydisposed in the first, second and third pixel regions, respectively,forming a pixel electrode over each of the red, green and blue colorfilter patterns and connected to one of the thin film transistors, andforming a common electrode over each of the red, green and blue colorfilter patterns and connected to one of the first, second and thirdcommon lines, the common electrode spaced apart from the pixelelectrode.

In another aspect, an array substrate for an LCD device includes asubstrate, gate lines on the substrate along a first direction, datalines formed along a second direction and crossing the gate lines todefine pixel regions, a common line between adjacent gate lines, a thinfilm transistor at each crossing point of the gate lines and the datalines, red, green and blue color filter patterns sequentially disposedin the pixel regions, respectively, a common electrode over each of thered, green and blue color filter patterns and connected to the commonline, and a pixel electrode over the common electrode and connected tothe thin film transistor, the pixel electrode overlapping the commonelectrode.

In another aspect, a manufacturing method of an array substrate for anLCD device includes forming gate lines on a substrate along a firstdirection, forming data lines along a second direction and crossing thegate lines to define pixel regions, forming a common line betweenadjacent gate lines, forming a thin film transistor at each crossingpoint of the gate lines and the data lines, forming red, green and bluecolor filter patterns over thin film transistor, the red, green and bluecolor filter patterns sequentially disposed in the pixel regions,respectively, forming a common electrode over each of the red, green andblue color filter patterns and connected to the common line, and forminga pixel electrode over the common electrode and connected to the thinfilm transistor, the pixel electrode overlapping the common electrode.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a view of schematically illustrating an LCD device accordingto the related art;

FIG. 2 is a cross-sectional view of schematically illustrating an arraysubstrate for a COA-type LCD device according to the related art;

FIG. 3 is a cross-sectional view of illustrating an array substrate fora COA-IPS mode LCD device according to the related art;

FIG. 4 is a schematic view of explaining dielectric constants of colorfilter patterns of FIG. 3;

FIG. 5 is an equivalent circuit of an LCD device according to a firstembodiment of the present invention;

FIG. 6 is a plan view of illustrating an array substrate for an LCDdevice according to the first embodiment of the present invention;

FIG. 7 is an equivalent circuit of an LCD device according to a secondembodiment of the present invention;

FIG. 8 is a schematic view of illustrating an array substrate for an LCDdevice according to a third embodiment of the present invention;

FIG. 9 is a plan view of illustrating an array substrate for an LCDdevice according to the third embodiment of the present invention; and

FIGS. 10A to 10C are cross-sectional views of illustrating an arraysubstrate for an LCD device in manufacturing processes according to thethird embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

FIG. 5 is an equivalent circuit of an LCD device according to a firstembodiment of the present invention.

In FIG. 5, gate lines G1, G2, G3 to Gn (n is a natural number) areformed along a first direction and spaced apart from each other. Datalines D1, D2, D3 to Dm (m is a natural number) are formed along a seconddirection and cross the gate lines G1, G2, G3 to Gn to define pixelregions P.

A thin film transistor T, a liquid crystal capacitor C_(LC) and astorage capacitor C_(ST) are formed at each pixel region P. The thinfilm transistor T is connected to a corresponding gate line G1, G2, G3or Gn and a corresponding data line D1, D2, D3 to Dm. The storagecapacitor C_(ST) is connected to the liquid crystal capacitor C_(LC)substantially in parallel.

A color filter layer 130 a, 130 b and 130 c is formed in each pixelregion P such that one color corresponds to one pixel region P. Here,the color filter layer 130 a, 130 b and 130 c is a stripe type in whichcolor filter patterns along the second direction are the same color andare connected to each other. The color filter layer includes red, greenand blue color filter patterns 130 a, 130 b and 130 c.

The liquid crystal capacitor C_(LC) is connected to the thin filmtransistor T and a corresponding common line 108 a, 108 b or 108 c. Thestorage capacitor C_(ST) is connected to the thin film transistor T anda storage line 106. The liquid crystal capacitor C_(LC) receives a datavoltage and a common voltage from the corresponding data line D1, D2, D3or Dm and the corresponding common line 108 a, 108 b or 108 c,respectively. The storage capacitor C_(ST) receives the data voltage anda storage voltage from the corresponding data line D1, D2, D3 or Dm andthe storage line 106, respectively.

The common voltage is a direct current (DC) voltage. The data voltage isan alternating current (AC) voltage. The data voltage alternates betweena positive polarity and a negative polarity with respect to the commonvoltage.

Storage capacitances of the storage capacitors C_(ST) are the same allover the area of the LCD device. The same storage voltage is applied toall pixel regions P through the storage line 106.

On the other hand, first, second and third common lines 108 a, 108 b and108 c are connected to respective liquid crystal capacitors C_(LC) atthe pixel regions P, which correspond to the red, green and blue colorfilter patterns 130 a, 130 b and 130 c, respectively. Different commonvoltages are applied to the liquid crystal capacitors C_(LC) through thefirst, second and third common lines 108 a, 108 b and 108 c,respectively, to compensate differences in pixel voltages due todifferent dielectric constants of the color filter patterns 130 a, 130 band 130 c.

That is, if the pixel voltages are alternately driven on basis of thesame common voltage when there is difference between the pixel voltages,positive and negative polarities of the pixel voltages are not uniform.Accordingly, there may be difference between the pixel voltages ofadjacent pixel regions, and the band-shaped speckles may occur.

However, the problem can be solved by applying the different commonvoltages to the liquid crystal capacitors C_(LC).

FIG. 6 is a plan view of illustrating an array substrate for an LCDdevice according to the first embodiment of the present invention.

In FIG. 6, a gate line 102 is formed on a substrate 100 along a firstdirection. A data line 120 is formed along a second direction. The gateline 102 and the data line 120 cross each other to define a pixel regionP. A thin film transistor T is formed at a crossing point of the gateline 102 and the data line 120. The thin film transistor T includes agate electrode 104, an active layer 112, a source electrode 116 and adrain electrode 118. The gate electrode 104 is connected to the gateline 102, and the source electrode 116 is connected to the data line120.

A storage line 106 and a common line 108 are formed along the firstdirection and are spaced apart from each other. The storage line 106 maybe adjacent to the gate line 102.

A color filter pattern 130 a, for example, a red color filter pattern,is formed in the pixel region P. Although not shown in the figure, agreen color filter pattern and a blue color filter pattern arerespectively formed in next two pixel regions along the first direction.The green color filter pattern may be thicker than the red and bluecolor filter patterns.

Although not shown in the figure, a black matrix may be further formedbetween the thin film transistor T and the color filter pattern 130 a.

A pixel electrode 132 a and 132 b and a common electrode 134 a and 134 bare formed in the pixel region P and are spaced apart from each other.Although not shown in the figure, the pixel electrode 132 a and 132 band the common electrode 134 a and 134 b are disposed over the colorfilter pattern 130 a.

The pixel electrode includes a first horizontal portion 132 a and firstvertical portions 132 b. The first horizontal portion 132 a is connectedto the drain electrode 118. The first horizontal portion 132 a overlapsthe storage line 106 to form a storage capacitor. The first verticalportions 132 b extend from the first horizontal portion 132 a along thesecond direction. The common electrode includes a second horizontalportion 134 a and second vertical portions 134 b. The second horizontalportion 134 a is connected to the common line 108. The second verticalportions 134 b extend from the second horizontal portion 134 a andalternate with the first vertical portions 132 b.

As stated above, the common electrode 134 a and 134 b receives adifferent common voltage from those in pixel regions adjacent to thepixel region P along the first direction.

Accordingly, the difference in the pixel voltages due to differentdielectric constants of the color filter patterns can be compensated,and images uniform qualities can be displayed.

FIG. 7 is an equivalent circuit of an LCD device according to a secondembodiment of the present invention.

In FIG. 7, gate lines G1, G2, G3 to Gn (n is a natural number) areformed along a first direction and spaced apart from each other. Datalines D1, D2, D3 to Dm (m is a natural number) are formed along a seconddirection and cross the gate lines G1, G2, G3 to Gn to define pixelregions P.

A thin film transistor T, a liquid crystal capacitor C_(LC) and astorage capacitor C_(ST) are formed at each pixel region P. The thinfilm transistor T is connected to a corresponding gate line G1, G2, G3or Gn and a corresponding data line D1, D2, D3 or Dm. The storagecapacitor C_(ST) is connected to the liquid crystal capacitor C_(LC)substantially in parallel.

A color filter layer 230 a, 230 b and 230 c is formed in each pixelregion P such that one color corresponds to one pixel region P. Here,the color filter layer 230 a, 230 b and 230 c is a stripe type in whichcolor filter patterns along the second direction are the same color andare connected to each other. The color filter layer includes red, greenand blue color filter patterns 230 a, 230 b and 230 c.

The liquid crystal capacitor C_(LC) is connected to the thin filmtransistor T and a corresponding common line 208 a or 208 b. The storagecapacitor C_(ST) is connected to the thin film transistor T and astorage line 206.

Storage capacitances of the storage capacitors C_(ST) are the same allover the area of the LCD device. The same storage voltage is applied toall pixel regions P through the storage line 206. The storage line 206may be united in all pixel regions P.

On the other hand, a first common line 208 a is connected to the liquidcrystal capacitors C_(LC) at the pixel regions P, which correspond tothe red and blue color filter patterns 230 a and 230 c, and a secondcommon line 208 b is connected to the liquid crystal capacitors C_(LC)at the pixel regions P, which correspond to the green color filterpattern 230 b. The first common line 208 a is connected to a firstcommon voltage source (not shown), and the second common line 208 b isconnected to a second common voltage source (not shown).

The same voltage is applied to the liquid crystal capacitors C_(LC)corresponding to the red and blue color filter patterns 230 a and 230 cbecause the red and blue color filter patterns 230 a and 230 c havesimilar dielectric constants. The voltage applied to the liquid crystalcapacitors C_(LC) corresponding to the red and blue color filterpatterns 230 a and 230 c is different from a voltage applied to theliquid crystal capacitors C_(LC) corresponding to the green color filterpattern 230 b.

An array substrate for the LCD device according to the second embodimentmay have the same structure as that of the first embodiment illustratedin FIG. 6.

FIG. 8 is a schematic view of illustrating an array substrate for an LCDdevice according to a third embodiment of the present invention. The LCDdevice is a COA type, in which a color filter layer is formed on thearray substrate.

In FIG. 8, red, green and blue color filter patterns 324 a, 324 b and324 c are formed over a substrate 300. A common electrode 328 is formedon each of the red, green and blue color filter patterns 324 a, 324 band 324 c. A pixel electrode 334 b is formed over the common electrode328. The pixel electrode 334 b overlaps the common electrode 328.

When voltages are applied to the common electrode 328 and the pixelelectrode 334 b, an electric field is induced between the commonelectrode 328 and the pixel electrode 334 b. At this time, even thoughcharges are induced in the color filter patterns 324 a, 324 b and 324 c,the charges may be screened by the common electrode 328 and may notaffect pixels corresponding to respective colors. Accordingly, thepixels can be uniformly driven without effects due to differentdielectric constants of the color filter patterns 324 a, 324 b and 324c, and images having uniform qualities can be displayed.

FIG. 9 is a plan view of illustrating an array substrate for an LCDdevice according to the third embodiment of the present invention.

In FIG. 9, a gate line 302 is formed on a substrate 300 along a firstdirection. A data line 314 is formed along a second direction. The gateline 302 and the data line 314 cross each other to define a pixel regionP. A thin film transistor T is formed at a crossing point of the gateline 302 and the data line 314. The thin film transistor T includes agate electrode 304, an active layer 310, a source electrode 316 and adrain electrode 318. The gate electrode 304 is connected to the gateline 302, and the source electrode 316 is connected to the data line314.

A common line 306 is formed along the first direction and is spacedapart from the gate line 302.

A color filter pattern 324 b, for example, a green color filter pattern,is formed in the pixel region P. Although not shown in the figure, a redcolor filter pattern and a blue color filter pattern are respectivelyformed in pixel regions adjacent to the pixel region P along the firstdirection. The same color filter pattern is formed in adjacent pixelregions P along the second direction.

Although not shown in the figure, a black matrix may be formed betweenthe thin film transistor T and the color filter pattern 324 b to preventlight incident to the active layer 310.

A pixel electrode 334 a and 334 b and a common electrode 328 are formedin the pixel region P. Although not shown in the figure, the pixelelectrode 132 a and 132 b and the common electrode 134 a and 134 b aredisposed over the color filter pattern 130 a. The common electrode 328has a flat shape and substantially corresponds to a size of the pixelregion P. The pixel electrode includes a horizontal portion 334 a andvertical portions 334 b. The horizontal portion 334 a is connected tothe drain electrode 318. The vertical portions 334 b extend from thehorizontal portion 334 a along the second direction. An insulating layer(not shown) is disposed between the common electrode 328 and the pixelelectrode 334 a and 334 b. The vertical portions 334 b overlap commonelectrode 328.

In the array substrate, widths of the vertical portions 334 b are narrowsuch that an electric field between the common electrode 328 and thevertical portions 334 b affects even a center of each vertical portion334 b. Accordingly, light leakage such as band-shaped disclination overthe electrodes of the LCD device can be minimized.

FIGS. 10A to 10C are cross-sectional views of illustrating an arraysubstrate for an LCD device in manufacturing processes according to thethird embodiment. FIGS. 10A to 10C correspond to the line X-X of FIG. 9.

In FIG. 10A, a gate line 302 of FIG. 9 and a gate electrode 304 areformed on a substrate 300 by deposing a conductive material and thenpatterning the conductive material. The metallic material may beselected from a metallic group including chromium (Cr), molybdenum (Mo),tungsten (W), aluminum (Al), copper (Cu) and titanium (Ti). A commonline 306 of FIG. 9 is simultaneously formed parallel to the gate line302 of FIG. 9.

A gate insulating layer 308 is formed on a substantially entire surfaceof the substrate 300 including the gate line 302 of FIG. 9, the gateelectrode 304 and the common line 306 of FIG. 9 by depositing aninsulating material. The insulating material may be selected from aninorganic insulating material group including silicon nitride (SiNx) andsilicon oxide (SiO₂).

Next, an active layer 310 and an ohmic contact layer 312 are formed onthe gate insulating layer 308 corresponding to the gate electrode 304 bydepositing intrinsic amorphous silicon and impurity-doped amorphoussilicon and then pattering the intrinsic amorphous silicon and theimpurity-doped amorphous silicon.

A data line 314, a source electrode 316 and a drain electrode 318 areformed on the substrate 300 including the active layer 310 and the ohmiccontact layer 312 by depositing a conductive material and thenpatterning the conductive material. The conductive material may beselected from the above-mentioned metallic group. Although not shown inthe figure, the data line 314 crosses the gate line 304 to define apixel region P. The source electrode 316 extends from the data line 314.The source and drain electrodes 316 and 318 are spaced from each otherover the gate electrode 304 and the active layer 310. After forming thesource and drain electrodes 316 and 318, a part of the ohmic contactlayer 312 between the source and drain electrodes 316 and 318 is removedto thereby expose the active layer 310.

The gate electrode 304, the active layer 310, the ohmic contact layer312, the source electrode 316 and the drain electrode 318 constitute athin film transistor T.

A first passivation layer 320 is formed on a substantially entiresurface of the substrate 300 including the data line 314, the sourceelectrode 316 and the drain electrode 318 by depositing one selectedfrom the above-mentioned inorganic insulating material group. The firstpassivation layer 320 protects the exposed surface of the active layer310. The first passivation layer 320 has relatively good adhesion withthe active layer 310, and defects can be minimized in an interfacebetween the passivation layer 320 and the active layer 310.

In FIG. 10B, a black matrix 322 is formed over the thin film transistorT by applying a black resin to a substantially entire surface of thesubstrate 300 including the first passivation layer 320 and thenpattering the black resin. The black matrix 322 may be omitted if thereis a black matrix corresponding to the thin film transistor T on anopposite substrate to the substrate 300.

Next, a color filter pattern 324 a, for example, a red color filterpattern, is formed in the pixel region P on the substrate 300 includingthe black matrix 322 by applying a red color resin to the substrate 300and then patterning the red color resin. Then, a blue color filterpattern 324 c and a green color filter pattern (not shown), for example,are formed in next pixel regions by the same method as the color filterpattern 324 a.

Here, although not shown in the figure, the green color filter patternmay be thicker than the red and blue color filter patterns touniformalize the color purities of the red, green and blue color filterpatterns.

Next, the color filter pattern 324 a, the black matrix 322 and the firstpassivation layer 320 are selectively removed to form a first draincontact hole 326 exposing the drain electrode 318.

In FIG. 10C, a common electrode 328 is formed on the color filterpattern 324 a by depositing a transparent conductive material and thenpattering the transparent conductive material. The common electrode 328has a plate-shape in the pixel region P. The transparent conductivematerial may be selected from a transparent conductive material groupincluding indium tin oxide and indium zinc oxide.

Next, a second passivation layer 330 is formed on a substantially entiresurface of the substrate 300 including the common electrode 328 bydepositing one selected from the above-mentioned inorganic insulatingmaterial group.

The second passivation layer 330 is selectively removed in a portioncorresponding to the first drain contact hole of FIG. 10B to therebyform a second drain contact hole 332 exposing the drain electrode 318.

A pixel electrode 334 a and 334 b is formed on the second passivationlayer 330 by depositing a transparent conductive material and thenpatterning the transparent conductive material. The transparentconductive material may be selected from the above-mentioned transparentconductive material group.

The pixel electrode includes a horizontal portion 334 a and verticalportions 334 b. The horizontal portion 334 a contacts the exposed drainelectrode 318. Although not shown in the figure, the vertical portions334 b extend from the horizontal portion 334 a.

In the present invention, even though the red, green and blue colorfilter patterns have different dielectric constants, there is no effectdue to the dielectric constants. Therefore, images having uniformqualities can be displayed.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the color filter substratefor an LCD device and manufacturing method thereof of the presentinvention without departing from the spirit or scope of the invention.Thus, it is intended that the present invention cover the modificationsand variations of this invention provided they come within the scope ofthe appended claims and their equivalents.

What is claimed is:
 1. An array substrate for an LCD device, comprising:a substrate; gate lines on the substrate along a first direction; datalines formed along a second direction and crossing the gate lines todefine pixel regions; a common line between adjacent gate lines; a thinfilm transistor at each crossing point of the gate lines and the datalines; red, green and blue color filter patterns sequentially disposedin the pixel regions, respectively; a common electrode over each of thered, green and blue color filter patterns and connected to the commonline; and a pixel electrode over the common electrode and connected tothe thin film transistor, the pixel electrode overlapping the commonelectrode wherein the green color filter pattern is thicker than the redand blue color filter patterns.
 2. The array substrate according toclaim 1, further comprising a black matrix between the thin filmtransistor and one of the red, green and blue color filter patterns ineach pixel region.
 3. The array substrate according to claim 1, whereinthe pixel electrode includes a horizontal portion and vertical portions,the horizontal portion connected to the thin film transistor, thevertical portions extending from the horizontal portion and overlappingthe common electrode.
 4. A manufacturing method of an array substratefor an LCD device, comprising: forming gate lines on a substrate along afirst direction; forming data lines along a second direction andcrossing the gate lines to define pixel regions; forming a common linebetween adjacent gate lines; forming a thin film transistor at eachcrossing point of the gate lines and the data lines; forming red, greenand blue color filter patterns over thin film transistor, the red, greenand blue color filter patterns sequentially disposed in the pixelregions, respectively; forming a common electrode over each of the red,green and blue color filter patterns and connected to the common line;and forming a pixel electrode over the common electrode and connected tothe thin film transistor, the pixel electrode overlapping the commonelectrode, wherein the green color filter pattern is thicker than thered and blue color filter patterns.
 5. The method according to claim 4,further comprising forming a black matrix in each pixel region betweenforming the thin film transistor and forming the red, green and bluecolor filter patterns.
 6. The method according to claim 4, furthercomprising forming a first passivation layer between forming the thinfilm transistor and forming the red, green and blue color filterpatterns and forming a second passivation layer between forming thecommon electrode and forming the pixel electrode.